Interpenetrating Networks for Delivery Systems

Client: Professor W. John Kao, School of Pharmacy & Department of Biomedical Engineering

Advisor: Professor Naomi Chesler, Department of Biomedical Engineering

Ashley HuthClaire FlanaganAdam Rieves

Jon Sass

Overview• Background Information

• Interpenetrating Networks (IPNs)• Competing Products• Past Semester

• Problem Statement• Design Requirements• Proposed Designs• Future Work• Questions

Problem Statement• To design a novel delivery mechanism

to reconstitute the components of an interpenetrating network (IPN).

Background: IPNs

*Kao, W.J.

What is an IPN?A bioactive wound dressing for

large surface area wounds

IPNConventional Dressings

Irregular Wound

Background: IPNs

• Kao, W.J.

Solution(drugs + matrix component)

Covalently Linked Therapeutic(s) and/orCell Adhesion Ligands

Soluble Therapeutic(s)

Biodegradable Gelatin Backbone

PEG-diacrylate(2-3.4 kDa )

in situ UV curing

IPNs are composed of multiple components

Clinical Application• Benefits

– Biocompatible– Moist healing environment– Conforms to irregular wounds– Covers large surface area wounds– Delivers drug cocktails

• Issues– Heat– Uneven administration– Lengthy application process

Current Administration TechniqueIngredients/drug(s) in singlecontainer

Mix1

Cover5

Heat2

3 Inject Syringe is use to administer solution

4 Curein 30 sec to obtain a rubbery film

6 Sustained Releasewhile the IPN biodegrades

Day7Day

3Day1

7 Clean

*Kao, W.J

Components•pegDA•Gelatin•Photoinitator•Water

Last Semester• Focused on optimizing IPN solution

composition– Gelatin dissolution impacts efficacy & administration of IPNs– Integrated laboratory & design-based research

• Developed IPN recipe • Modified IPN administration

This Semester• Administration technique • Product packaging• Further laboratory research

Design Requirements• Minimal preparation and effort required to

administer the IPN• Compartmentalization • Even spray pattern• Uniform solution• Straightforward mixing procedure• Disposable • Can be sterilized • Low-cost• Few parts

Competing Products• Duoject Medical Systems Inc.

– Inter-Vial• Debiotech

– Clip’n’ject• U-Mix

– Travel Bottle• Hansplast

– Spray Bandage

Design 1: Syringe • Liquid in plunger• Powder stored in

barrel• Mechanism to release

liquid into powder• Hand mixing• Hand powered

delivery• Luer-Lock spray tip

Design 1: Syringe• Pros

– All in one packaging– Easy application– Controllable spray rate

• Cons– Custom manufacturing required– Moving parts

Design 2: Pressurized Bottle• Manual pressure

vacuum• Unique cap design

– Facilitates stirring mechanism

• Perforated seal

Design 2: Pressurized Bottle• Pros

– Parts readily available– Few modifications necessary– Spray is sustained for approx. 20 sec

• Cons– Pressure building is laborious– All parts must be packaged separately– Pressure feature comes at a cost ($14)– Only one size is available

Design 3: Spray Bottle

• Threaded straw • Blades puncture inner

container• Single pump, single

spray• Includes mixing

mechanism

Design 3: Spray Bottle• Pros

– Incorporates mixing mechanism– Provides slow release of photo-initiator

• Cons– Laborious application technique– Non-standard parts

Design MatrixCriteria Weight

Design 1 Syringe

Design 2 Pressurize

Design 3 Spray

Mixing Procedure 15 10 9 12Uniform Solution 10 6 7 7Compartmentalization 10 9 5 8Parts Availability 10 7 9 6Application Ergonomics 10 8 6 4Safety 10 8 6 8Cost 10 5 3 7Sterility 5 5 3 4Scalability 5 5 2 4Spray Pattern 5 4 5 2Client Preference 5 5 5 3Photo-initiator Protection 5 3 5 4TOTAL 100 75 65 69

Future Work• Test cold-water soluble gelatin• Develop-Manufacture-Test prototype• Research photoinitiators• Continue patent search